1 . Technical Field
The present disclosure relates to a light emitting element that includes a semiconductor layer, an upper electrode disposed on an upper surface of the semiconductor layer, and a lower electrode disposed on a lower surface of the semiconductor layer.
2 . Background Art
There have been light emitting elements in which a “pad” is disposed on at each of two adjacent corners of an approximately rectangular upper surface of a semiconductor layer, and a “fine wire electrode” is disposed in a grid shape extending from the pad electrode, as described in JP2013-197197A.
However, with such a conventional structure, uneven emission tends to occur. Generally, a higher current density occurs in a region close to the pad to which the wire for supplying current from an external power source is connected, and even with a fine wire electrode, the current density decreases as the distance from the pad increases. As a result, stronger emission occurs near the pad, which tends to result in uneven brightness in the emission of the light emitting element as a whole.
Certain embodiments of the present invention have been devised in view of such circumstances, and an object thereof is to provide a light emitting element that can emit light more uniformly.
According to certain embodiments of the present invention, a light emitting element includes a semiconductor layer, an upper electrode disposed on an upper surface of the semiconductor layer, and a lower electrode disposed on a lower surface of the semiconductor layer. The light emitting element has an approximately rectangular shape in a plan view. In the plan view, the upper electrode includes a first extending portion extending in an approximately rectangular shape with four sides, along outer periphery of the semiconductor layer, a first pad portion connected to a first side among the four sides of the first extending portion, a second pad portion connected to a second side which is opposite to the first side, and a second extending portion and a third extending portion each disposed in a region surrounded by the first extending portion and respectively connecting the first pad portion and the second pad portion. With respect to a first straight line connecting the first pad portion and the second pad portion with a shortest distance, the second extending portion is disposed in a region closer to the third side of the four sides, and the third extending portion is disposed in a region closer to the forth side which is opposite to the third side. On a second straight line perpendicularly bisecting the first straight line, a distance between the second extending portion and the third extending portion is equal to or greater than a shortest distance between the first extending portion and the second extending portion, and equal to or greater than a shortest distance between the first extending portion and the third extending portion.
According to certain embodiments of the present invention, it is possible to obtain a light emitting element in which uneven current density on the upper surface of the semiconductor layer can be reduced, which allows for more uniform emission.